Effect of surfactants and hydrophilic polymers on the stability of an antihypertensive drug candesartan cilexetil: Evaluation by HPLC.

OBJECTIVES: The objective of this study is to investigate the effect of surfactants (polysorbate 80 and sodium lauryl sulphate) and hydrophilic polymers (polyvinylpyrrolidone and polyethylene glycol 6000) on the stability of candesartan cilexetil under isothermal stress conditions (100°C, 48h). METHODS: HPLC method was employed to evaluate the drug content and formation of degradation products in stress samples. Drug and degradation products were separated on Hypersil BDS C18 (250×4.6mm, 5µ) column using acetonitrile-water (pH 2.8) in the ratio of 85:15% v/v as a mobile phase. RESULT: Similar degradation behaviour of drug was observed with polyvinylpyrrolidone, polyethylene glycol 6000 and polysorbate 80; four common degradation peaks were observed at the retention time of 3.7, 4.5, 7.8 and 11minutes. One extra common degradation peak of very low intensity was also observed with polyethylene glycol 6000 and polysorbate 80 at the retention time of 4.2min. The drug was eluting at the retention time of 5.4min. In the case of sodium lauryl sulphate, two prominent degradation peaks were observed at the retention time of 3.7 and 13.25min along with few very low-intensity degradation peaks. CONCLUSION: The drug showed 41%, 64%, 72% and 98% degradation in presence of polyvinylpyrrolidone, polyethylene glycol 6000, polysorbate 80 and sodium lauryl sulphate, respectively.

A blue arsenomolybdic acid-crystal violet ion-associate pair paving the way for the field detection of arsenic in groundwater.

A simple visual colorimetric method based on arsenomolybdic acid-crystal violet ion-associate pair formation is described for the detection of As in groundwater at about 10, 25 and 50 µg L-1 levels. The pair exhibits light green coloration at ≤5 µg L-1 and blue colorations of distinctly different intensities at about 10, 25 and 50 µg L-1 concentrations of arsenic. High sensitivity is achieved by the preconcentration of As that entails simultaneous sorption of both As(III) and As(V) from groundwater on covellite (CuS) and, later, their elution as As(V), which subsequently participates in the formation of arsenomolybdic acid. The interference in the color development from PO43-ions that are as efficiently sorbed on CuS and eluted as the oxyanions of As is eliminated by their selective removal by Ce4+ ions under basic (pH ∼ 8.5) conditions. The removal is caused by the formation of cerium phosphate and its co-precipitation with calcium hydroxide. SiO42- ions do not interfere in the process as they are not sorbed by CuS. Groundwater containing ≤0.5 mg L-1 P and ≥200 mg L-1 total dissolved solid can be conveniently analysed by the method. The direct sensing of As(III) as well as As(V), the use of benign and easily available chemicals, the absence of any hazardous by-product, undiminished applicability in sunlight, the testing procedure lasting only for about 30 min, and rapidity are the major advantages of the method. Thus, the method is potentially well-suited for the on-site testing of groundwater potability under different regulations.

Neonatal Meningitis with Septicemia by Elizabethkingia meningoseptica : A Case Report.

Elizabethkingia is ubiquitary aerobic bacillus abundantly found in the community as well as hospital environments. Elizabethkingia meningoseptica is an emerging nosocomial pathogen with an elemental ability to acclimate and survive in diversified environmental circumstances. Prompt diagnosis and an early therapeutic intervention are preponderant in the management of these infections. We report a case of meningitis with septicemia caused by E. meningoseptica in a 1-day-old outborn neonate. The child was stabilized with anticonvulsants and, based on laboratory findings, the neonate was started on ciprofloxacin in addition to symptomatic management. The child responded well to the treatment and was discharged on day 7 after treatment initiation. Perceptive treatment protocols backed with accurate laboratory evidence remain instrumental to avert unpropitious outcomes while combatting rare multidrug-resistant opportunistic infections.

Analysis of caffeic acid derivatives in echinacea extracts by liquid chromatography particle beam mass spectrometry (LC-PB/MS) employing electron impact and glow discharge ionization sources.

A liquid chromatography-particle beam/mass spectrometry (LC-PB/MS) method with electron impact (EI) and glow discharge (GD) ionization sources is presented for the determination of caffeic acid derivatives in echinacea tinctures. In this work, two commercially available echinacea ethanolic extracts were used as the test samples for the separation, identification, and quantification of the caffeic acid derivatives (caffeic acid, chlorogenic acid, cichoric acid, and caftaric acid), which are suggested to have beneficial medicinal properties. Detailed evaluations of the two primary controlling parameters for EI (electron energy and source block temperature) and GD (discharge current and pressure) sources were performed to determine optimal instrument operation conditions. The mass spectra obtained from both ion sources provide clear and simple molecular fragmentation patterns for each of the target analytes. The absolute detection limits for the caffeic acid derivatives were determined to be at subnanogram levels for both the EI and GD sources. The separation of the caffeic acid derivatives in echinacea was accomplished by reversed-phase chromatography using a C(18) column and a gradient elution system of water containing 0.1% trifluoroacetic acid and methanol, with an analysis time of less than 40 min. A standard addition method was employed for the quantification of each of the caffeic acid derivatives in the tincture.

Liquid chromatography-particle beam electron ionization mass spectrometry method for analysis of botanical extracts: evaluation of ephedrine alkaloids in standard reference materials.

The preliminary validation of a high-performance liquid chromatography particle beam mass spectrometry method (HPLC-PB/MS) with electron impact ionization source for analysis of botanical extracts is presented. The LC-PB/MS system was evaluated for the analysis of ephedrine alkaloids using ephedra-containing National Institute of Standards and Technology dietary supplement standard reference materials (SRMs) 3241 Ephedra Sinica Stapf Native Extract and 3242 Ephedra Sinica Stapf Commercial Extract. The ephedrine alkaloids were separated by reversed-phase chromatography using a phenyl column at room temperature. A linear gradient method with a mobile phase composition varying from 5:95 [MeOH:0.1% trifluoroacetic acid (TFA) in water] to 20:80 (MeOH:0.1% TFA in water) at a flow rate of 1.0 ml/min, with an analysis time of less than 20 min, was used. The source block temperature was evaluated to determine the optimal operating conditions by monitoring the intensities and fragmentation patterns of the ephedrine alkaloids. Ephedrine and N-methylephedrine were taken as a representative of the test alkaloids. The LODs on the sub-nanogram level were achieved, with ephedrine, pseudoephedrine, and methylephedrine in the SRMs quantified by a standard addition method with recoveries of > or = 86% and RSDs of < or = 14% (n = 3).

A review on adverse event profiles of epidermal growth factor receptor-tyrosine kinase inhibitors in nonsmall cell lung cancer patients.

The epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of EGFR-mutant nonsmall cell lung cancer (NSCLC). These EGFR TKIs demonstrate a different adverse event (AE) profile as compared to conventional chemotherapy agents. They are more commonly associated with cutaneous AEs and diarrhea while hematological AEs occurred commonly with chemotherapy agents. These AEs are the extension of pharmacological effect and occur as a result of blockade of EGFR-regulated pathways in the skin and gastrointestinal tract. This review article sheds light on the safety profile of first-, second-, and third-generation EGFR TKIs based on data obtained from several clinical trials conducted in NSCLC patients and highlights trials comparing these agents with the conventional chemotherapy agents. The strategies to manage EGFR TKI-related AEs are also reviewed.

Studies of mercury pollution in a lake due to a thermometer factory situated in a tourist resort: Kodaikkanal, India.

Kodaikkanal, India, suffered mercury contamination due to emissions and waste from a thermometer factory. Kodai Lake is situated to the north of the factory. The present study determined mercury in waters, sediment and fish samples and compared the values with those from two other lakes, Berijam and Kukkal. Total mercury (Hg(T)) of 356-465 ng l(-1), and 50 ng l(-1) of mercury in methyl mercury form were seen in Kodai waters while Berijam and Kukkal waters showed significantly lower values. Kodai sediment showed 276-350 mg/kg Hg(T) with about 6% methyl mercury. Berijam and Kukkal sediments showed Hg(T) of 189-226 mg/kg and 85-91 mg/kg and lower methylation at 3-4% and 2%, respectively. Hg(T) in fish from Kodai lake ranged from 120 to 290 mg/kg. The results show that pollution of the lake has taken place due to mercury emissions by the factory.

Removal and preconcentration of inorganic and methyl mercury from aqueous media using a sorbent prepared from the plant Coriandrum sativum.

A sorbent prepared from the plant Coriandrum sativum, commonly known as coriander or Chinese parsley, was observed to remove inorganic (Hg2+) and methyl mercury (CH3Hg+) from aqueous solutions with good efficiency. Batch experiments were carried out to determine the pH dependency in the range 1-10 and the time profiles of sorption for both the species. Removal of both the forms of mercury from spiked ground water samples was found to be efficient and not influenced by other ions. Column experiments with silica-immobilized coriander demonstrated that the sorbent is capable of removing considerable amounts of both forms of mercury from water. The sorption behaviour indicates the major role of carboxylic acid groups in binding the mercury. The studies suggest that the sorbent can be used for the decontamination of inorganic and methyl mercury from contaminated waters.

A combined treatment approach using Fenton's reagent and zero valent iron for the removal of arsenic from drinking water.

Studies on the development of an arsenic remediation approach using Fenton's reagent (H2O2 and Fe(II)) followed by passage through zero valent iron is reported. The efficiency of the process was investigated under various operating conditions. Potable municipal water and ground water samples spiked with arsenic(III) and (V) were used in the investigations. The arsenic content was determined by ICP-QMS. A HPLC-ICPMS procedure was used for the speciation and determination of both As(III) and (V) in the processed samples, to study the effectiveness of the oxidation step and the subsequent removal of the arsenic. The optimisation studies indicate that addition of 100 microl of H2O2 and 100 mg of Fe(II) (as ferrous ammonium sulphate) per litre of water for initial treatment followed by passing through zero valent iron, after a reaction time of 10 min, is capable of removing arsenic to lower than the US Environmental Protection Agency (EPA) guideline value of 10 microg/l, from a starting concentration of 2 mg/l of As(III). Using these suggested amounts, several experiments were carried out at different concentrations of As(III). Residual hydrogen peroxide in the processed samples can be eliminated by subsequent chlorination, making the water, thus, processed, suitable for drinking purposes. This approach is simple and cost effective for use at community levels.

Metronomic therapy: chemotherapy revisited.

Cytotoxic antiproliferative chemotherapeutic agents are the mainstay of treatment in cancers. Chemotherapy is usually administered every 2-3 weeks. Along with acute toxicity and long-term effects of cumulative doses, this strategy potentially allows regrowth of the tumor in the interval period and leads to the emergence of resistant populations of tumor cells. Moreover, even with intense chemotherapy, the outcome is stagnating for most of the tumors. There has been recent interest in the use of chemotherapy in fractionated doses which is far below the maximum tolerated dose. This is called metronomic scheduling of chemotherapy. Here, we review the biology and evidence for metronomic chemotherapy.

On-line speciation of inorganic and methyl mercury in waters and fish tissues using polyaniline micro-column and flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS).

A simple and efficient method for the determination of ultra-trace amounts of inorganic mercury (iHg) and methylmercury (MeHg) in waters and fish tissues was developed using a micro-column filled with polyaniline (PANI) coupled online to flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS) system. Preliminary studies indicated that inorganic and methyl mercury species could be separated on PANI column in two different speciation approaches. At pH <3, only iHg could be sorbed and almost no adsorption of MeHg was found (speciation procedure 1). If the sample solution pH is approximately 7, both MeHg and iHg species could be sorbed on the PANI column. Subsequently both the Hg species were selectively eluted with 2% HCl and a mixture of 2% HCl and 0.02% thiourea respectively (speciation procedure 2). The adsorption percentage of iHg on the PANI column was unchanged even with acidity of the sample solution increased to 6 mol L(-1). Therefore, an acidic solution (5 mol L(-1) HCl), used for ultra-sound assisted extraction of the mercury species from biological samples, was used directly to separate MeHg from iHg in the fish tissues (tuna fish ERM-CE 463, ERM-CE 464 and IAEA-350) by PANI column using speciation procedure 1. The determined values were in good agreement with certified values. Under optimal conditions, the limits of detection (LODs) were 2.52 pg and 3.24 pg for iHg and MeHg (as Hg) respectively. The developed method was applied successfully to the direct determination of iHg and MeHg in various waters (tap water, lake water, ground water and sea-water) and the recoveries for the spiked samples were in the range of 96-102% for both the Hg species.

Performance and emission characteristics of a low heat rejection engine with different air gap thicknesses with Jatropha oil based bio-diesel.

The research work on alternate fuels has been the topic of wider interest in the context of depletion of fossil fuels and increasing of pollution levels of the engines with conventional fossil fuels. Alcohols and vegetable oils are considered to replace diesel fuels as they are renewable in nature. However, use of alcohols in internal combustion engines is limited in India, as these fuels are diverted to PetroChemical industries and hence much emphasis is given to the non-edible vegetable oils as alternate fuels in internal combustion engines. However, the drawbacks of low volatility and high viscosity associated with non-edible vegetable oils call for hot combustion chamber, provided by low heat rejection (LHR) diesel engine. Investigations are carried out on a LHR diesel engine with varied air gap thicknesses and injection pressures with jatropha oil based bio-diesel at normal temperature. Performance is improved with high degree of insulation with LHR engine with vegetable oil in comparison with conventional engine (CE) with pure diesel operation.

On-line preconcentration and recovery of palladium from waters using polyaniline (PANI) loaded in mini-column and determination by ICP-MS; elimination of spectral interferences.

The applicability of polyaniline (PANI) for the on-line preconcentration and recovery of palladium from various water samples has been investigated. Batch experiments were performed to optimize conditions such as pH and contact time to achieve quantitative separation of Pd spiked at high (microg ml(-1)) and low levels (ng ml(-1)). During all the steps of the removal process, it was found that Pd was selectively removed by PANI even in the presence of various ions. Quantitative removal of Pd occured in the entire studied pH range (1-12) and the K(d) value was found to be >10(6). Kinetic studies show that a contact time of <4 min was adequate to reach equilibrium. The retained Pd was subsequently eluted with a mixture of HCl and thiourea, optimized using a factorial experimental design approach. ICP-OES was used for the micro-level determinations of Pd whereas ICP-MS was used for the determination of Pd at sub-ppb levels. Breakthrough curve using column experiments demonstrated that PANI has an excellent ability to accumulate up to approximately 120 mg g(-1) of Pd from synthetic sample solutions. A preconcentration factor of about 125 was achieved for Pd when 250 ml of water was passed. PANI columns prepared were used up to 10 times in consecutive retention-elution cycles without appreciable deterioration in their performance. The proposed on-line method also has the ability to remove interfering elements Cu and Y for the determination of Pd in waters by ICP-MS. The reported method has been applied successfully for the determination of Pd in ground water, lake water sea-water and waste water samples. The recoveries were found to be >95% in all cases. These studies indicate that PANI has an excellent ability to preconcentrate Pd from various waters making the method very promising for the determination of Pd.

Electron-impact and glow-discharge ionization LC-MS analysis of green tea tincture.

A liquid chromatography-particle-beam mass spectrometer (LC-PB/MS) with interchangeable electron-impact (EI) and glow-discharge (GD) ion sources was evaluated for future application in analysis of botanical extracts. In this work a green tea tincture was characterized for a series of catechin components (catechin, epicatechin, epigallocatechin, and epigallocatechin gallate (EGCG)) and caffeine. Special emphasis was given to EGCG and caffeine, because they are important in determining the possible health effects of the green tea. The effects of instrument operating conditions were evaluated for the EI and GD ionization sources to determine their effect on analyte intensities and fragmentation patterns. These studies furnished information about the effects of these conditions in determining possible ionization pathways in the two ion sources. The mass spectra of these compounds obtained with the GD ion source are EI-like in appearance, with clearly identified molecular ions and fragmentation patterns that are easily rationalized. The absolute limits of detection for EGCG and caffeine were, respectively, 11 ng and 0.77 ng for the EI source and 3.2 ng and 0.61 ng for the GD source. The PB/EIMS and PB/GDMS combinations can be operated in a flow-injection mode, wherein the analyte is injected directly into the mobile phase, or coupled to high-performance liquid chromatography (HPLC), enabling LC-MS analysis of complex mixtures. A reversed-phase chromatographic separation of the green tea tincture was performed on a commercial C18 column using a gradient of water (containing 0.1% TFA) and ACN. Quantification of EGCG and caffeine was performed by the standard addition method. The amounts of EGCG and caffeine in the tested green tea tincture were each approximately 14 mg mL-1.

Control of aldehyde emissions in the diesel engines with alcoholic fuels.

The major pollutants emitted from compression ignition (CI) engine with diesel as fuel are smoke and nitrogen oxides (NOx). When the diesel engine is run with alternate fuels, there is need to check alcohols (methanol or ethanol) and aldehydes also. Alcohols cannot be used directly in diesel engine and hence engine modification is essential as alcohols have low cetane number and high latent hear of vaporization. Hence, for use of alcohol in diesel engine, it needs hot combustion chamber, which is provided by low heat rejection (LHR) diesel engine with an air gap insulated piston with superni crown and air gap insulated liner with superni insert. In the present study, the pollution levels of aldehydes are reported with the use of methanol and ethanol as alternate fuels in LHR diesel engine with varying injection pressure, injection timings with different percentage of alcohol induction. The aldehydes (formaldehyde and acetaldehyde) in the exhaust were estimated by wet chemical technique with high performance liquid chromatograph (HPLC). Aldehyde emissions increased with an increase in alcohol induction. The LHR engine showed a decrease in aldehyde emissions when compared to conventional engine. However, the variation of injection pressure showed a marginal effect in reducing aldehydes, while advancing the injection timing reduced aldehyde emissions.

Speciation of Cr(III) and Cr(VI) in waters using immobilized moss and determination by ICP-MS and FAAS.

The possibility of using moss (Funaria hygrometrica), immobilized in a polysilicate matrix as substrate for speciation of Cr(III) and Cr(VI) in various water samples has been investigated. Experiments were performed to optimize conditions such as pH, amount of sorbent and flow rate, to achieve the quantitative separation of Cr(III) and Cr(VI). During all the steps of the separation process, Cr(III) was selectively sorbed on the column of immobilized moss in the pH range of 4-8 while, Cr(VI) was found to remain in solution. The retained Cr(III) was subsequently eluted with 10ml of 2moll(-1) HNO(3). A pre-concentration factor of about 20 was achieved for Cr(III) when, 200ml of water was passed. The immobilized moss was packed in a home made mini-column and incorporated in flow injection system for obtaining calibration plots for both Cr(III) and Cr(VI) at low ppb levels that were compared with the plots obtained without column. After separation, the chromium (Cr) species were determined by inductively coupled plasma mass spectrometry (ICP-MS) and flame atomic absorption spectrometry (FAAS). The sorption capacity of the immobilized moss was found to be approximately 11.5mgg(-1) for Cr(III). The effect of various interfering ions has also been studied. The proposed method was applied successfully for the determination of Cr(III) and Cr(VI) in spiked and real wastewater samples and recoveries were found to be >95%.

A rapid ultrasound-assisted thiourea extraction method for the determination of inorganic and methyl mercury in biological and environmental samples by CVAAS.

A rapid ultrasound-assisted extraction procedure for the determination of total mercury, inorganic and methyl mercury (MM) in various environmental matrices (animal tissues, samples of plant origin and coal fly ash) has been developed. The mercury contents were estimated by cold vapour atomic absorption spectrometry (CVAAS). Inorganic mercury (IM) was determined using SnCl(2) as reducing agent whereas total mercury was determined after oxidation of methyl mercury through UV irradiation. Operational parameters such as extractant composition (HNO(3) and thiourea), sonication time and sonication amplitude found to be different for different matrices and were optimized using IAEA-350 (Fish homogenate), IM and MM loaded moss and NIST-1633b (Coal fly ash) to get quantitative extraction of total mercury. The method was further validated through the analysis of additional certified reference materials (RM): NRCC-DORM2 (Dogfish muscle), NRCC-DOLT1 (Dogfish liver) and IAEA-336 (Lichen). Quantitative recovery of total Hg was achieved using mixtures of 5% HNO(3) and 0.02% thiourea, 10% HNO(3) and 0.02% thiourea, 20% HNO(3) and 0.2% thiourea for fish tissues, plant matrices and coal fly ash samples, respectively. The results obtained were in close agreement with certified values with an overall precision in the range of 5-15%. The proposed ultrasound-assisted extraction procedure significantly reduces the time required for sample treatment for the extraction of Hg species. The extracted mercury species are very stable even after 24h of sonication. Closed microwave digestion was also used for comparison purposes. The proposed method was applied for the determination of Hg in field samples of lichens, mosses, coal fly ash and coal samples.